Garbage disposals are designed for grinding up and washing away kitchen refuse with the touch of a switch. Most garbage disposers fit the standard drain outlet and are either hard-wired or plugged into a 120-volt box or receptacle. The horsepower and size needed for a garbage disposal depend on the homeowner's general use. If you are a heavy user, consider a unit with a larger horse power and an auto-reverse feature. Before buying a garbage disposer, check local laws and be sure your sewer system can handle a disposer. Garbage disposers are mounted to the underside of a sink and are designed to store waste food in a hopper chamber.